This invention relates to novel copper(I) oxalate complexes and their use for removing CO and unsaturated hydrocarbons from gas streams. More particularly, CO is removed from gas streams by using the reaction of CO with Cu.sub.2 O and oxalic acid in an inert organic solvent to form Cu.sub.2 (CO).sub.2 C.sub.2 O.sub.4. CO can be displaced by reacting Cu.sub.2 (CO).sub.2 C.sub.2 O.sub.4 with unsaturated hydrocarbon.
U.S. Pat. No. 2,604,391 discloses a gas-producing charge for use in a non-detonating decomposition. The composition contains nitroguanidine or guanidine nitrate and a copper compound such as copper powder, cupric oxide, cuprous chloride or cuprous oxylate. A. P. Glaskova, Explosivstoffe, 23, 137-145 (1973) describes the effects of catalysts on the deflagration of certain classes of explosives. Cu.sub.2 C.sub.2 O.sub.4 and its effects on ammonium perchlorate are shown in FIG. 8 and Table V.
It is known that certain copper(I) salts form complexes with olefins and acetylenes. For example, cuprous chloride is known to form complexes with both ethylene and acetylene. U.S. Pat. No. 3,401,112 teaches a method of separating a mixture of hydrocarbons having differing degrees of unsaturation using a copper(I) salt of the formula CuXA where XA is an anion, X is oxygen or fluorine and A is the remainder of the anion. In general, anions of the cuprous salts are anions of inorganic, organic or organo-inorganic acids wherein the pK.sub.a valves are in the order of 4.6 or less. CuXA forms a cuprous complex with said unsaturated hydrocarbon. U.S. Pat. Nos. 3,754,047 and 3,755,487 disclose a process for separating complexible ligands such as olefins, acetylenes, aromatics and CO from a feed-stream using cuprous salts such as CuAlCl.sub.4, CuBF.sub.4, CuOOCCF.sub.3, CuPF.sub.6 and the like.
It is also known that certain cuprous salts can absorb CO from solutions. A review of the early literature and a detailed study of absorption of CO in aqueous cuprous ammonium lactate may be found in J. Appl. Chem. (London), 15, 17-28 (1965). Cuprous formate is an early example of a cuprous salt for CO absorption.
U.S. Pat. No. 3,630,676 describes a process for removing CO from mixed gas streams using a cuprous fluoroborate or cuprous fluorophosphate containing complex plus an aromatic and/or olefinic hydrocarbon. U.S. Pat. No. 4,042,669 discloses a process for removing CO from a gas mixture by treating the gas mixture with an absorbent containing a Cu(I) salt of an organic sulfonic acid or a dialkyl phosphate. U.S. Pat. No. 4,048,292 relates to a method of removing CO from CO.sub.2 -free gas streams using a liquid absorbent system containing a copper ammonium formate or acetate.